1. Field of the Invention
This invention relates to kitchen blenders. More specifically, the invention relates to blenders in which a container having a rotary cutter in its bottom wall normally sits on a power base, a motor in the power base being releaseably coupled to the cutter.
2. Description of Related Art including Information Disclosed under .sctn..sctn.1.97 to 1.99
The prior art is loaded with examples of kitchen blenders comprising containers which sit on a power base with automatically engaged coupling means on the bottom of the container and top of the base. Examples are Pat. No. 2,284,155 which issued May 26, 1942 to M. J. Landgraf; Pat. No. 2,758,623 which issued Aug. 14, 1962 to N. Malz et al; and Pat. No. 3,175,594 which issued Mar. 30, 1965 to I. Jepson et al. In the past the containers for such blenders have been more or less symmetrical about the axis of the cutter.
Some of the containers have featured longitudinal inward fins or vanes which assist in the blending process. For instance, in the Landgraf patent, the cutter swirls the fluid within the container in a general rotary direction past the fins which deflect the fluid inward and upward or downward to assist in the blending operation. This phenomenon is generally treated in the Landgraf patent.
The prior art has, as well, disclosed a number of food processors wherein, for safety, the motor has been disabled until the cover is in place. This avoids the risk of injury by someone reaching down into the container while the cutter is rotating. Such devices, for instance as that shown shown in the U.S. Pat. No. 4,184,641 which issued Jan. 22, 1980 to M. Coggiolia, have involved a lateral tab on the container cover which causes actuation of an interlock switch only when the cover is in place. The interlock switch is normally at the level of the cover.
Generally, such interlock switch means have not been used on blenders because the distance between the top of the container and the cutter has been great enough so that accidental insertion of one's hand all the way to the cutter has not been likely.